Transformation behaviour and one-way shape memory effect in Fe-Mn-Si shape memory alloys

Humboldt-Fellow, on leave from Centro Atomico Bariloche, 8400 Bariloche, and CRUB, Universidad National del Comahue, Argentina.     

New insights into the peculiar behavior of laminar burning velocities of hydrogen–air flames according to pressure and equivalence ratio

Hydrogen is a clean and energetic fuel, and its oxidation mechanism is a subset of the oxidation mechanisms of all hydrocarbons. Therefore, the validation of the available kinetic schemes is of great importance. In the current study, experimental measurements of laminar flame speeds and modeling studies were performed for H₂–air premixed flames over a wide range of equivalence ratios (0.5–4.0) and pressures (0.2–3 bar). The large scale in mixture and thermodynamic conditions allows a better understanding of the peculiar behavior of hydrogen flame speeds with pressure. Two very recent detailed chemical kinetic mechanisms for hydrogen combustion were selected. Excellent agreement was observed between calculations and experimental results, confirming the validity of the kinetic schemes selected. The kinetic analyses performed allow proposing an explanation for the nonmonotonic variation of hydrogen/air flame speed with pressure observed in the experiments.     

Overlap-Based Cell Tracker

In order to facilitate the extraction of quantitative data from live cell image sets, automated image analysis methods are needed. This paper presents an introduction to the general principle of an overlap cell tracking software developed by the National Institute of Standards and Technology (NIST). This cell tracker has the ability to track cells across a set of time lapse images acquired at high rates based on the amount of overlap between cellular regions in consecutive frames. It is designed to be highly flexible, requires little user parameterization, and has a fast execution time.     

Induced nanosecond absorption in InP:Fe

Induced absorption was observed in an InP:Fe crystal under nanosecond pulse illumination at 1.06-μm wavelength. The maximum induced absorption was 0.05 cm^-1 when probed at a 1.06-μm wavelength and 0.30 cm^-1 when probed at a 1.30-μm wavelength. The kinetics are studied together with the photocurrent giving the recombination times of holes (100 ns) at room temperature and an estimate for that of electrons (0.5 ns). The induced absorption is attributed to a population redistribution of the different iron impurity states. Computer simulations are able to explain all the features found in the experiments and give values for the photoionization cross sections, in particular for the unknown cross section Fe^2+*→Fe³⁺+e^-     

Modell eines Roboters aus Formgedächtnismetall

Zusammenfassung Im Fahmen diese Beitrags wird des Modell eines Roboters vorgestellt, der seine Bewegung ohne jegliche elektromotorische oder pneumatische Antriebe aufsührt. Entsprechende Bauelemente sind übedflüszig, da der Werkstoff, aus dem der Raboter gefertigt ist, die Greiffunktion selbst durchführt. Dies geschieht über das Signal einer Temperatur?nderung, so da? die Bauteile lediglich erw?rmt oder abgekühll werden müssen, um die Greifbewegung zu realisieren. Diese Eigenschaft von Werkstoffen nennt man ?Formged?chtnis?: Der Werkstoff erinnert sich bei Temperatur?nderungen an seine vorherige Form und nimmt diese selbst?ndig an. Es handelt sich dabei, um eine v?llig neue Werkstoffeigenschaft, nicht um eine lediglich verbesserte. Der Formged?chtniseffekt ist hinsichtlich seiner Ursachen sehr komplex und neu, so da? zum besseren Verst?ndnis die Grundlagen des Effektes vertieft in diesem Bericht beschrieben werden.     

Cytologic examination of the breast: a safe, simple, and accurate technique

Aspiration cytology of the breast is a rapid, accurate diagnostic technique which can be easily and safely performed in the physician's office in conjunction with clinical examination of the breast. When evaluated by an experienced pathologist, cytologic preparations are useful in assessing solid masses in the breast or abnormal secretions of the nipple. The procedure has few complications, and spread of tumor cells along the needle track is not likely.     

A broadband high-frequency electrical impedance tomography system for breast imaging.

Bio-electric impedance signatures arise primarily from differences in cellular morphologies within an organ and can be used to differentiate benign and malignant pathologies, specifically in the breast. Electrical impedance tomography (EIT) is an imaging modality that determines the impedance distribution within tissue and has been used in prior work to map the electrical properties of breast at signal frequencies ranging from a few kHz to 1 MHz. It has been suggested that by extending the frequency range, additional information of clinical significance may be obtained. We have, therefore, developed a new EIT system for breast imaging which covers the frequency range from 10 kHz to 10 MHz. The instrument developed here is a distributed processor tomograph with 64 channels, capable of generating and measuring voltages and currents. Electrical benchmarking has shown the system to have a SNR greater than 94 dB up to 2 MHz, 90 dB up to 7 MHz, and 65 dB at 10 MHz. In addition, the system measures impedances to an accuracy of 99.7 % and has channel-to-channel variations of less than 0.05 %. Phantom imaging has demonstrated the ability to image across the entire frequency range in both single- and multiplane configurations. Further, 96 women have participated safely in breast exams with the system and the associated conductivity spectra obtained from 3-D image reconstructions range from 0.0237 S/m at 10 kHz to 0.2174 S/m at 10 MHz. These findings are consistent with impedance values reported in the literature.     

VIAN: A Visual Annotation Tool for Film Analysis

While color plays a fundamental role in film design and production, existing solutions for film analysis in the digital humanities address perceptual and spatial color information only tangentially. We introduce VIAN, a visual film annotation system centered on the semantic aspects of film color analysis. The tool enables expert‐assessed labeling, curation, visualization and Classification of color features based on their perceived context and aesthetic quality. It is the first of its kind that incorporates foreground‐background information made possible by modern deep learning segmentation methods. The proposed tool seamlessly integrates a multimedia data management system, so that films can undergo a full color‐oriented analysis pipeline.